Microhabitat use by Mediterranean ribbed newts: newts in highly fluctuating conditions?

Abstract

ABSTRACT Ribbed newts (genus Pleurodeles) are among the few species of amphibians present in open, dry and warm southern Mediterranean habitats. However, the factors that determine the presence of these species in such xeric environments remain poorly understood. We characterised the microhabitat niches of the three species of the genus (P. nebulosus, P. poireti and P. waltl). We used temperature–humidity probes and described the variation in the vegetative composition of their habitats. We found that the three species of this genus use sparsely vegetated habitats, exposed to high seasonal temperatures (above 35°C) and to broad intra-annual fluctuations in air temperature and humidity. The capacity of the three species to occupy microclimatically fluctuating environments explains why these urodeles are broadly distributed in disturbed landscapes in southern Mediterranean regions, where no other species of urodeles occur. Ribbed newts are highly adaptable to changing environments, which is advantageous under highly unstable Mediterranean hydrological regimes.